GPT-5.6 Luna at Max Reasoning Matches Opus 5 at 1/6th the Cost
JeremyNguyenPhD · x · 2026-08-01
Users on X recommend trying GPT-5.6 Luna with Max reasoning effort enabled in Codex/ChatGPT Work. Although off by default, this setting reportedly yields 6x the usage and delivers coding performance comparable to Anthropic's Claude Opus 5 (Medium) or Sol Medium at a fraction of the cost.
Related event: Enabling Codex Max Reasoning Boosts Performance and Cuts Costs(3 posts)→
More from coding & agent
- 'LLM code is sloppy' rebutted with real ffmpeg code: identical if/else branches in a top library — kingslyj · 2026-10-16
- Office-editing tool calls need file, worktree and unit: lessons from dsh-univer-office — FunDistribution6537 · 2026-10-16
- Architect MD workflow: Gemini one-shot outputs that beat Opus, via 5-lens plan critique — oikk01 · 2026-10-16
- Prove a coding agent actually ran the tests: check artifacts, not approvals — ComprehensiveShake76 · 2026-10-16
- Building an acceptance harness for AI spreadsheet edits: allowlists, recalc checks, idempotency — ukdicha-modakkk · 2026-10-16
- Agent actions need checks outside the model: NVIDIA demos lean on guardrails amid wave of real agent incidents — Creamy-And-Crowded · 2026-10-16